Can someone refresh my memory as to why we might need a selection of shims? are the pressures usually so far off as to not be abradeable? Do the springs wear out?
Just looked at my Haynes and it says that increasing a shim's thickness by 0.05mm increases break pressure by 5 atmospheres... I make that 73psi. Surely that's not accurate enough for balanced idling. So abrading is surely the only way to go [speaking as a generally pretty handy DIYer :wink: ] I can see everyone ending up with a pile of spare expensive washers which will never get used :shock:
Quote from: "Mark(The Miser)UK"Just looked at my Haynes and it says that increasing a shim's thickness by 0.05mm increases break pressure by 5 atmospheres... I make that 73psi. Surely that's not accurate enough for balanced idling. So abrading is surely the only way to go [speaking as a generally pretty handy DIYer :wink: ] I can see everyone ending up with a pile of spare expensive washers which will never get used :shock: Generally you use the shim to get within 5 bar... and then abrade the spring to hone in.Having a pile of shims makes it much much quicker to get within shooting distance within 1 disassembly/reassembly.
New complete injectors supposedly come calibrated and are generally pretty close in my experience... although some will want to dial them in even closer.Most of us DIY dudes just buy new nozzles and/or play with different nozzles in reused injector bodies. In this case the breaking pressure can be all over the map (just did some Merc nozzles and the breaking pressure when reassembled was 205 bar... puts the "pop" in "pop tester" !).One other nuance... as injectors settle in and/or wear the pop pressure changes as well.So, if you're gonna play with nozzles... a whack of shims is a handy thing indeed. 'Course, some of us need to get a life !! ;-)
What is the price of a bulk shim package?How often do you rebuild injectors with new nozzles?